To the Editor:—After 35 years as a well-established diagnostic procedure, positive contrast myelography still arouses a certain uneasiness, and there is widespread fear of the medicolegal implications of the use of iodized oils in the spinal canal. In dogs, the intrathecal introduction of such oils appears to be regularly followed by the formation of adhesions around the cauda equina, with or without attendant progressive morbidity. Whether or not such adhesions occur in man in response to myelographic contrast media, or, if they do, whether they have morbid significance has not been established. Reports of chronic morbidity following myelography have been unconvincing. The very few deaths that have occurred immediately upon introduction of the oil are almost certainly attributable to idiosyncrasy. Aspiration of the oil, a painful procedure, is possibly harmful in itself. Whether a small residue is less damaging than a large one is not apparent; yet total removal